(a) Field of the Invention
The present invention relates to a signal detection method, and a receiver.
(b) Description of the Related Art
As wireless communication systems are being developed, speed-related requirements are becoming more and more important. In order to satisfy such requirements, it is needed to use a wide frequency bandwidth, but frequency resources are limited. Accordingly, a multiple input, multiple output (MIMO) antenna technology is used in order to transmit larger amounts of data while using the limited frequency bandwidths.
Among the multiple input multiple output antenna techniques, there are basically a spatial diversity technique where the transmission reliability is enhanced by obtaining diversity profits corresponding to the square of the number of transceiver antennas, and a spatial multiplexing (SM) technique where different data streams are made through different transmission routes.
With the double spatial multiplexing technique, mutual interference is liable to occur between different data streams, and hence the receiver detects and decodes signals considering the interference. The optimal way is to calculate the likelihood of the respective data bits considering the detection and the decoding simultaneously, but it is difficult to operate in such a way because it involves excessive complexity regarding the dimension of constellations and the number of antennas.
Accordingly, an iterative detection decoding (IDD) technique where the likelihood of respective bits is calculated in respective cases of detection and decoding, and the calculated results are repeatedly exchanged so as to calculate the final likelihood of the respective bits, has been introduced. However, such a technique also still involves high complexity so that it is difficult to practically realize the desired system.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.